수리동력학적 및 초음파 캐비테이션 슬러지 전처리 장치의 비교 연구 = Comparisons of Sludge Pre-Treatment Systems: Hydrodynamic vs Ultrasonic Cavitation

국문 초록 (Abstract)

슬러지 전처리 방법으로 상용화되어 있는 cavitation을 이용한 방법은 서로 다른 원리, 초음파발생기(sonotrode)와 수리동역학을 이용하고 있지만 이들 방법의 효율을 비교한 연구는 없었다. 본 연구에서는 이 두 전처리 방법에서 슬러지 가용화 효율, 전처리 후 입경변화, 전처리 전후의 메탄 생성량 변화를 평가하였다. 두 방법에 있어서 단위 에너지 투입량 당 가용화 효율은 유사하였으며, 최대 가용화 효율은 0.18 kWh/L에서 302 mg △SCOD/g TS이었다. 전처리 초기에는 슬러지의 floc 해체가 주로 일어났고, 전처리가 진행됨에 따라 1 ㎛ 이하의 입자가 증가하여 셀이 파괴되는 것을 확인할 수 있었다. BMP 시험 결과 슬러지의 메탄가스 발생량은 전처리 방법별 차이는 없이 최대 24.3%까지 증가하였으나, 투입 에너지에 비례하여 증가하지는 않았다. 비록 두 방법의 에너지 효율을 유사하지만 운영 및 유지비와 향후 에너지효율 개선 잠재력 면에서 볼 때 수리동력학적 원리를 이용하는 방법이 현장 적용에 유리하다고 판단된다.

다국어 초록 (Multilingual Abstract)

Sludge pre-treatment utilizing cavitation is one of the commercialized methods at present. Cavitation can be generated by two different methods, sonotrode and hydrodynamic principle, and there has been no direct comparison between the two methods. In this study, solubilization efficiency, changes in sludge size distribution, and the methane production potential after pre-treatment by the two methods were compared. The maximum solubilization efficiency per unit energy input with the two methods was similar, and was 302 mg △SCOD/g TS at the energy input of 0.18 kWh/L. Break-up of sludge flocs were dominant during the early period of pre-treatment, while cell disintegration continued through the pre-treatment with the increase in the number of particles with less than 1 ㎛. BMP test results indicated that the methane potential increased up to 24.3% without differences between the two pre-treatments, and the increase in methane potential did not proportional to energy input. Although the energy efficiency of the two methods was quite similar, hydrodynamic methods might be a better choice for field application considering the operation and maintenance cost, and its potential improvement in energy efficiency.

참고문헌 (Reference)

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